NOTES ON (E, 2E) EXPERIMENTS WITH EXCITED ATOMS IN THE INITIAL-STATE

Recent experiments on the single ionization of excited hydrogen-like a toms revived new interest in the theoretical questions related to thes e processes. In order to make some predictions for future experiments we consider here for fast projectiles different types of triple differ ential cross sections and their angular distributions for both small a nd large momentum transfer. We also pay special attention to states wi th high quantum number n and to the influence of electron-ion interact ions in the final state. We give the kinematical conditions to observe a new diffractional structure for symmetric collisions and the main p eak for asymmetric collisions.